How did Antarctic succumb to ice age?
Washington: Researchers now know how the Antarctic Peninsula first succumbed to ice during a prolonged period of global cooling and how it has warmed up significantly in recent decades.
The rapid decline of glaciers along the peninsula has led to widespread speculation about how the rest of the continent's ice sheets will react to rising global temperatures.
"The best way to predict future changes in the behaviour of Antarctic ice sheets and their influence on climate is to understand their past," said Rice University marine geologist John Anderson who led the study.
In the warmest period in earth's past 55 million years, Antarctica was ice free and forested.
The continent's vast ice sheets, which today hold more than two-thirds of our freshwater, began forming about 38 million years ago, according to a Rice University statement.
The Antarctic Peninsula, which juts farther north than the rest of the continent, was the last part of Antarctica to succumb to ice.
It is also the part that has experienced the most dramatic warming in recent decades. Its mean annual temperatures rose as much as six times faster than mean annual temperatures worldwide.
"There's a longstanding debate about how rapidly glaciation progressed in Antarctica," said Sophie Warny, a Louisiana State University geologist.